OPTICAL LEVEL CONTROL METHOD, OPTICAL LEVEL CONTROLLER, WAVELENGTH MULTIPLEX OPTICAL NETWORK

摘要

An optical level controller comprising variable optical attenuators for attenuating optical input signals of the wavelengths of a wavelength multiplex signal by variable attenuations and control units for automatically controlling the attenuations so that the optical output level of each variable optical attenuator may be a target level while the optical input signal is in a normal state, further comprising sensing units for detecting light beam cut-off and cut-off cancel of the optical input signal of each variable optical attenuator, wherein the control unit adjusts the attenuation to a first predetermined value when the sensing unit detects cut-off, and to a second predetermined value when the sensing unit detects cut-off cancel, and changes its control to automatic control.